/*
 * Copyright (c) 2020 - present, Inspur Genersoft Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.iec.edp.caf.rpc.api.spi;

import io.iec.edp.caf.rpc.api.common.ServiceCenterProviderType;
import io.iec.edp.caf.rpc.api.entity.ServiceUnitDefinition;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;

import java.util.HashMap;
import java.util.Map;
import java.util.ServiceLoader;

public interface ServiceCenterProvider {
    default ServiceCenterProviderType getType() {
        return ServiceCenterProviderType.Custom;
    }

    String discover(ServiceUnitDefinition serviceUnitDefinition);

    default void registry(ServiceUnitDefinition serviceUnitDefinition){

    }

    default void registry(){

    }

    static ServiceCenterProvider getServiceCenterProvider() {
        return ServiceCenterProvider.ServiceCenterSelector.serviceCenterProvider;
    }

    class ServiceCenterSelector {
        private static ServiceCenterProvider serviceCenterProvider = null;

        static {
            Log log = LogFactory.getLog(ServiceCenterProvider.class);
            Map<ServiceCenterProviderType, ServiceCenterProvider> serviceCenterProviderMap = new HashMap<>();

            ServiceLoader<ServiceCenterProvider> resolvers = ServiceLoader.load(ServiceCenterProvider.class);
            //默认ServiceCenterProvider只允许有一个
            for (ServiceCenterProvider resolver : resolvers) {
                if (log.isDebugEnabled()) {
                    log.debug("current serviceCenterProvider type [" + resolver.getType() + "] current serviceCenterProvider [" + resolver.getClass().getName() + "]");
                }

                serviceCenterProviderMap.put(resolver.getType(), resolver);
            }
            serviceCenterProvider = serviceCenterProviderMap.get(ServiceCenterProviderType.Custom);
            if (serviceCenterProvider == null) {//如果没有定义服务中心，用默认空实现代替
                serviceCenterProvider = serviceCenterProviderMap.get(ServiceCenterProviderType.Default);
            }
            Assert.notNull(serviceCenterProvider, "[serviceCenterProvider] is null, please check.");
        }
    }
}
